Grinding machine



Sept. 11, 1928.

F. P. BROWN GRINDING MACHINE Fild March 23, 1927 5 Sheets-Sheet l INl/'EN TOR.

Sept. 11, 192s.

F. E. BROWN GRINDING MACHINE Filed March 23, 1927 3 Sheets-Sheetl 2 A TTORNEYS.

Sept. 11, 192s.

1,683,859 .F. P. BROWN GRINDING MACHINE Filed March 25, 1927 3 sheets-sheet 3 NI/ENTOR.

/dfzci fa W/ A TTORNEYS.

Patented Sept. 11, 1928.

FRANCIS P. BROWN, OF PROVIDENCE,

OIF RHODE ISLAND.

RHODE ISLAND, ASSIGNOR TO BROWN & SHARPE MANUFACTURING COMPANY, F PROVIDENCE, RHODE ISLAND, A CORPORATION GRINDING- MACHINE.

. Application led March 23, 1927. Serial No. 177,653.

This invention relates to an improved construction of grinding machine, and has for 'one of its objects to provide means on such a machine for applying a tension on the grinding Wheel feed mechanism, Which'will o-perate effectively to influence the wheel in a direction away from the surface of the work being acted upon by the Wheel either when the wheel is positioned to operate externally or internally on the work.

A further object of t-he invention is the provision of a tensioning device for a so-called universal type of grinding machine which is preferably designed to act from the swivel center of the wheel support to influence the support and the wheel mounted thereon in a direction away from that surface of the work being ground for the purpose of taking up lost motion of the feeding mechanism.

A still further object of the invention is vthe provision swiveling center of the grinding wheel support through which a flexible tensioning connector extends, one end being connected to the wheel support and the other end to the tensioning weight on the other device.

The invention further consists in the provision of means in the grinding wheel supporting parts by which the point of attachment of the tensioning member may be adjusted to either the forward or rearward side of the pivoting center, wlierebytension is applied to the wheel support in a direction away from that surface of the work being acted upon, for

either an internal or external grinding operaion.

A still further object of the invention is the provision of a screw actuated nut member adjustably mounted in the grinding wheel supporting parts and to which nut member a flexible tensioning connector is attached and by means of the operation of which screw the nut may be adjusted to move the point of connection of this tensioning member to either the forward or rearward side of the swivelling center. l

With these and other objects in View, the invention consists of certain novel features of construction, as will bemore fully described, and particularly pointed out in the appended claims. Y

In the accompanying drawings: Figure 1 is a plan view of a universal type of grinding machine to which my improved of a tubular pivotal shaft at thef l sioning device is attached and indicating in dotted lines the wheel as being adapted to be swung into different operating positions.

Figure 2 is a sectional elevation through the cross feed mechanism showing the tubular shaft with a tensioning device extending therethrough and vapplied to the i grinding Wheel support.

Figure 3 is a diagrammatic view showing the tensioning device as applied -to the wheel support which is arranged to grind the ex- Y ternal surface of the work.

Figure 4 is a diagrammatic view showing my improved device as applied to a grinding machine which is arranged to grind the internal surface of the work.

Figure 5 is a top view showing one arrangement of cross-feed gearing.

Figure 6 is a perspective view illustrating the tension chain as leading up through the tubular shaft and adapted to be led either for- ,wardly or rearwardly therefrom over antifriction rolls to be connected to the grinding wheel support.

Figure 7 is a perspective view showing the under side of the adjustable nut member which is adapted to be mounted on the grinding wheel support to move the point of connection of the flexible tension chain to either side of the swivel center of this wheel support.

Figure 8 is a fragmental sectional view showing the adjustable nut member illustrated n Fig. 7, as mounted in its guide in the wheel stand slide.

It is well known that tension Weights have been applied to the plain type of grinding machines to take upthe wear and lost motion of its cross feed mechanism but such a tendevice has never been app-lied to the universal type of grinding machine in such a way as to be eective on the feeding mechanism both for external and internal grinding, to apply tension to the wheel support in a direction 'away from that surface of the work being acted upon; and to accomplish this in a simple and effective way, I have formed the vertically-disp-osed short shaft, which is at the axial center of the swivelling motion of the wheel sup-port7 in hollow or tubular form and have extended a flexible meinber, such as a chain or the like, up through this tubular shaft and have connected its upper end to the grinding wheel support and wheel 14, shaft 15, worm its lower end to a tensioning device such as a weight or the like to apply tension to the wheel through its support in a direction away from the surface of the work being acted upon, and arrangements have also been made whereby the point of attachment of this chain or flexible member to the grinding wheel support may be moved to positions either forward or to the rear of the axial center of this tubular shaft, whereby tension may be applied to the wheel through its support in a direction from the surface of the work being treated either when grinding externally or internallyA on the work; and the following is a detailed description of the` present lembodiment of my invention and showing one arrangement by which these advantageous results may be accomplished B the term rinding wheel su ort in.

y g e PP the specification and claims, I mean any or 'all of the parts which support the grinding wheel either directly or indirectly and which are operated by the cross-feed mechanism to move this wheel towards and from the work.

With reference to the drawings, 10 designates the frame of a so-called universal type of grinding machine on which is mounted the swivel bed 11 which supports the usual wheel. stand slide 12 and on which slide is mounted the grinding wheel' 13 by any of the usual means. The cross-feed for this wheel stand slide may be first effected through a hand 16, worm wheel 17, hollow, vertically-disposed shaft 18 and a pinion gear 19 acting on the rack 20, which latter is connected to the wheel stand slide l2 and on which is mounted the grinding wheel 13 in the bearing members-22.

This grinding wheel as shown in Figures l, 2 and 3 is arranged to operate externally upon the work 23, the latter being arranged to be supported in the carriage 24 in any usual way. I/Vhen it is desired to grind internally on a piece of tubular work such as that illustrated at 25, in Figure 5, a somewhat smaller sized grinding wheel 26 is mounted on the end of a spindle and inserted into the tube.,l this internal grinding wheel being supported on a bracket 27 attached to the support 28.

As is well known it is found necessary, in

y order to prevent the grinding wheel from biting into and injuring the work to apply tension to the grinding Wheel support to take up the wear or lost motion of the cross-feed mechanism. When grinding the work externally the tension on the feed parts is in one direction and when grinding the work internally tension on these parts is applied in the opposite direction and therefore I have constructed a tensioning device that is able to apply tension as desired in either of these directions but always in a direction away from the work; and to accomplish this in a simple and effective Way, I have provided a nut member 29 which slides towards and from the work in the groove 30 in the wheel stand slide 12, see Figure 8. At one end of this nut member is a socket member 31 to which the end 32 of the flexible chain 33 is connected while at the opposite end o'l this nut member 29 is formed a threaded lug 34which is engaged by the feed screw 35. To the lower end of the flexible chain 33 is secured the counterweight 36, the chain being arranged to lead up through the tubular shaft 18 over the anti-friction roll 37 in the bracket 39, see Figure, when the nut is in its forward position, as illustrated in Figure 2, which position it takes to effect tension in the proper direction while grinding externally upon the work, but when it is desired to grind the internal surface of the Work, as illustrated inl Figure 4, the nut 29 by action of the screw 35 is drawn rearwardly so that its point of' chainattachment 31 is positioned on the opposite or reaward side of the axial center -of the tubular shaft 18 to draw over the opposite anti-friction roll 38. In other words. the flexible chain is connected to the slide or wheel support at a point on the same side of the axial center of the tubular shaft as the position of the work bears to the axis of rotation of the grinding wheel.

By extending the tension chain or connector through the axial center of the grinding wheel support I provide at this center, a point of direction cont-rol of the tension force which point is intermediate the limits of travel of the wheel support, it will be noted that the tension will always be applied towards this center or point of control although the direction of tension toward this point may be shifted to act in opposite directions With relation to this point and will he properly applied to the parts even though the grinding wheel is arranged to grind eX- ternally or internally 0r when it is moved to different required working angles such for instance as those suggested in dotted lines in Figure 1.

My improved device for applying tension to the Wheel support is very simple in its arrangement, is practical in its construction and is efficient in' its action and by its use the required tension may be applied to .a grindingwheel support of a universal grinder in Whatever position the parts may be adlongitudinally j usted to grind different surfaces of the work.

1. In a grinding machine, a support for the work, a grinding` wheel, a support for said wheel, means for feeding the wheel support relative to the work within certain limits of travel, a tensioning means having a point of direction control of the tension force intermediate the limits of travel of the wheel support and means for shifting the direction of application of such tension force at saidI point to operate in one or the other of opposite directions toward said-point to take up wear of said feeding means.

2. In a grinding machine, a support for the work, a grinding wheel, a support for said wheel, means for feeding the wheel support relative to the work within certain limits of travel, a tensioning means having a point of direction control of the tension force intermediate the limitsof travel'of the wheel support and means for shifting the direction of application of such tension force across said point to operate in one or the other of opposite directions toward said. point for ap-w plying tensioning to said grinding wheel.

3. In a. grinding machine, asuppoit for the work, a grinding wheel, a suppoi't for said wheel mounted on a swivelling center, means for feeding the wheel support radially to said center and relative to the work. means for 'applying tension to said wheel to take up wear on said feeding means and means operable to shift the direction of said tension in opposite directions with reference to said cent-er and work.

4. In a grinding machine, a work support, a hollow shaft, a bed plate swivelly mounted about said shaft as an axis, a wheel stand slide having a grinding wheel mounted thereon, means for adjusting said slide and grinding wheel carried thereby towards and from said support and radially of said axis, a flexible chain connected to said slide at a point removed from the axis .of said shaft and extending through said hollow shaft, tensioning means on said chain, means for varying the point of connection of said chainto said slide to opposite sides of the axis of said sha-ft whereby the effective action of said tensioning means may tend to move said grinding wheel relative tothe surface worked upon as desired. l

5. In a grinding machine, asupport for the work, a grinding wheel, aA support for said wheel, a tubular shaft on which said support is pivot-ally `mounted, means for .and a flexible connection feeding the wheel and support radially to said shaft and relative to the work, a member carried by said wheel support, a weight, leading from said weight through said tubular'shaft to said member to apply tension to the wheel and its support and means forl moving said member' relative to said wheel support to opposite sides of the axis of said shaft to vary the direction of the tension as desired.

6. In a grinding machine, a work support,

a hollow shaft, a bed plate swivelly mounted about said shaft as an axis, a wheel stand slide having a grinding wheel mounted thereon, means for adjusting said slide and grinding wheel carried thereby towards and from said support and radially of said axis, antifriction rolls adjacent the end of said shaft on opposite sides of the axis and in line with the movement of said slide toward and from said support, a flexible chain connected to said slide at a point removed from the axis of said shaft and extending over one of said rolls and through said hollow shaft, tensioning means on said chain, inea-ns for varying the point of connection of said chain to said slide to opposite sidesof the axis of said shaft whereby the effective action of said tensioning means may tend to move said` grinding wheels relative to the surface worked upon as desired. l

7. In a, grinding machine, a work support, ahollow shaft, a bedplate swivelly mounted about said shaft as an axis, a wheel stand slide having a grinding wheel mounted thereon, a rack carrie-d by said slide, al pinion gear on said hollow shaft engaging said rac-k,

means for rotating said hollow sha-ft to adjust saidgrinding wheel towards and from said work support and radially of said axis, a nut carried by said slide and mounted for movement in a rectilinear path -across the axis of said hollow sha-ft, a iexib-le chain connected to said nut and extending through said hollow shaft, a weight on said chain, means for -moving said nut to points at op-- posite sides of the axis of said shaft whereby the effective tension o-f said weight may tend tomove said grinding wheel relative to the surface worked upon as desired.

In testimony whereof I afiix my signature.

iiRANoisr. BRowN. j 

